Project Details
Projekt
The detection of antiherbivore secondary compounds in the fossil record and their potential role in defense against insects
Applicant
Professor Dr. Jes Rust
Subject Area
Palaeontology
Term
from 2018 to 2023
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 348043586
Fossil evidence indicates that plants and insects were interacting soon after macroscopic ecosystems originated on land, and herbivory ‒ the consumption of living plant tissues ‒ is an ancient strategy that extends to the Early Devonian about 410 million years ago. As such their interactions are complex and important components of ancient and modern ecosystems. However, only mechanical defenses have been studied for fossil plants, since chemical defenses are not easy to assess in the fossil record. Modern studies of antiherbivore defenses indicate that plants have evolved two major strategies for contending with arthropod herbivores. The accommodationist strategy allows photosynthetic tissue to be accessed by insect herbivores by production of palatable, deciduous, thin-leaved foliage with short lifespans. The herbivore defensive strategy, on the other hand, is employs evergreen, sclerophyllous leaves with long lifespans that are highly defended by wide-ranging physical and chemical deterrents. The goal of this project is to use solid phase microextraction gas chromatography (SPME GC-MS) and time of flight secondary ion mass spectrometry (ToF-SIMS) to analyze well-preserved fossil plants to identify any preserved traces of chemical defenses, and to understand the evolution and development of chemical defenses. We are focusing on three exceptionally preserved floras: the 67 million-year-old latest Cretaceous Hell Creek Formation, the 305 million-year-old Late Pennsylvanian Calhoun Coal of the Mattoon Formation, and the 382 million-year-old Devonian Catskill Formation. The analyses of these fossils will be compared to analyses of fresh and decayed modern analogues and pure alkaloids known to be involved in modern chemical defenses. This project answer two questions about chemical defenses: 1. What chemicals were involved in the defense systems of the targeted lineages through time? 2. Is the morphology of the chemical defense strcutres (e.g., trichomes and oil body cells) decoupled from the actual chemicals they contain? Furthermore, the methods developed in this study can be used to study other fossils with the potential to preserve chemical defenses.
DFG Programme
Research Units
